ES2585181T3 - Cleaning procedure - Google Patents

Abstract

A cleaning process comprising the steps of (i) contacting feed water successively with one or more sets of a first cation exchange resin material and second with an anion exchange resin material to produce amplified water wash (ALA) that has a water hardness less than 5 ° FH and a pH value that is different by more than 0.5 pH units from the pH value of the feed water, said pH value being greater than 8, 5, in which the resins are regenerated by using an electric field, (ii) mixing said ALA with a low environmental impact detergent product (LEIP) containing from 0 to 5% by weight of the total LEIP composition and it comprises at least 10% by weight, preferably at least 25% by weight, more preferably at least 40% by weight, of surfactant, to obtain a washing liquor; and (iii) treating the substrates to be cleaned with said wash liquor.

Description

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DESCRIPTION

Cleaning procedure Field of the invention

The present invention relates to the field of tissue cleaning procedures. The invention especially relates to a water treatment process for obtaining a water that is suitable for use with detergents of low environmental impact.

Background of the invention

In recent years we have been increasingly aware of the impact of human activities on the environment and the negative consequences this may have. The ways to reduce, reuse and recycle resources are increasingly important. Tissue washing is one of the many domestic activities that have a significant environmental impact. This is partly due to the use of conventional detergent products, which tend to be relatively complex compositions with a variety of ingredients. Over the years, the legislation has banned some ingredients in different countries due to its harmful effects on the environment. Examples include certain non-ionic surfactants and detergent builder additives such as phosphates. The use of phosphates in detergents has been linked to rising levels of phosphates in surface waters. It is believed that the resulting eutrophication causes an increase in algal growth. The increased growth of algae in stagnant surface waters leads to the depletion of oxygen in the deeper water layers, which in turn causes a general reduction in the overall water quality.

Although some ingredients of conventional laundry detergent products may have a limited environmental effect, the energy involved in their production adversely affects the environmental impact during their life cycle. The analysis of the life cycle usually estimates the environmental impact of a product in the different phases, such as the production of raw material, the production of the product itself, the distribution to the end user, the use of the product through, for example, the consumer and discharge after use. The environmental impact may include factors such as eutrophication, greenhouse effect, acidification and formation of photochemical oxidants. With respect to laundry detergent products, the additional ingredients necessarily add cost, volume and weight to the product, which in turn requires more packaging material and transportation costs. Additional ingredients usually require a more complex production process. However, it is difficult to reduce the number or amount of ingredients without reducing the cleaning efficiency.

One of the most bulky ingredients in normal laundry detergents is the so-called detergent builder additives, such as zeolites, phosphates and carbonates. Currently, detergent builder additives are added to the 2f rapa washing detergent formulations for their ability to sequester hardness ions such as Ca and Mg. The reduction of the hardness ions is something necessary to avoid the deposition of soaps on the dirt, to avoid the precipitation of the anionic surfactants, to maximize the stability of the colloid and to reduce the calcium-dirt-substrate interaction and the dirt interaction - dirt to improve the elimination of dirt. In addition to its positive effects, detergent builder additives can also have negative effects on laundry procedures. For example, detergent builder additives frequently generate insoluble materials during washing, both by themselves and by precipitate formation. For example, zeolites are insoluble and can cause fouling of the tissues and heating elements of the washing machines and precipitates of the calcium detergent builder additive can result in a higher redeposition.

From the above, it will be evident that, on the one hand, the removal of hardness ions is required to achieve a good cleaning capacity, while, on the other hand, the presence of detergent builder additives in washing detergents. Clothing contributes significantly to its environmental impact. Additionally, detergent builder additives may also have negative effects on the performance of a laundry procedure.

An attractive solution to the above problems may be the removal of the hardness ions from the wash water before it comes into contact with the tissues and the detergent solution. Ion exchange is a possible technique to eliminate hardness ions from tap water, which allows the elimination of reinforcing detergent additives from detergent, thus reducing their environmental impact. In a recent Hitachi patent (US-A-6557382), water softening based on ion exchange is described. Ionic exchange removes hardness ions (Ca2 + and Mg2 +) from water by exchanging them with what are called substitution ions, usually Na + or H +, which are stored in ion exchange resins. The resin is depleted when the mayone of the substitution ions have been replaced by hardness ions. However, to recover the resin, which is also called resin regeneration, a strong recovery ion solution is generally applied to the resin. These are exchanged for ions that have been removed from the water and regenerate the resin. To this end, a concentrated saline solution or a strong acid or basic solution is normally used, which is undesirable for application in the washing of domestic clothes due to the negative environmental impact, high cost and lack of comfort and suitability for the user. Therefore, it is desirable to regenerate exchange resins

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ionic by means of a non-contaminating procedure that is especially suitable for the application of procedures for washing domestic laundry.

WO-A-01/30229 discloses a washing machine that has a water supply system and a water softening system that can be regenerated without substances or additives, preferably by EDI (electrodeionization). The softening system comprises anionic and cationic resins.

US-A-2825666 discloses a water demineralization unit in an automatic dishwasher. The unit uses electricity along with two ion exchange resins.

Other bulky ingredients in the usual hand laundry detergents are so-called buffers, for example carbonate, disilicate or metasilicate. These buffer components are added to the detergent formulations to reach and maintain the desired pH of the wash solution. The pH of a wash solution is usually maintained above 10 to improve the removal of fatty dirt and particles. Thus, on the one hand, maintaining a high pH is necessary to ensure good cleaning efficiency while, on the other, the presence of buffers in laundry detergents contributes to its environmental impact, as noted above. .

Consequently, one of the objects of the present invention is to find a cheap process that has a low environmental impact to eliminate hardness ions from tap water and to modify the pH. Another object of the present invention is to discover a method for removing hardness ions from tap water and modifying the pH of said tap water in a way that is comfortable and simple for consumers. A further object of the invention is to discover a suitable method for treating tap water in such a way that a water that is suitable for use with a low environmental impact detergent product (LEIP) is obtained, as defined herein. document), in tissue cleaning procedures. A further object of the invention is to discover a cleaning procedure in which the water obtained from said water treatment procedure can be used suitably in domestic cleaning applications, such as in an automatic washing machine.

A known process for water treatment is the so-called electrodeionization procedure (EDI), known from WO-A-01/30228 which combines ion exchange and electrodialysis. The resulting hybrid procedure does not require chemical regeneration products. An EDI module may consist, for example, of a repeated combination of a dilution chamber containing anionic and cationic exchange resins confined between anionic and cationic exchange membranes, a concentration chamber and, finally, electrolyte chambers. Water can flow through the different chambers in separate loops. Cations, such as Ca2 + and Mg2 + are attracted to the cathode, and the anions are attracted to the anode, where the resin acts as a conductive medium. The ions are transferred to the concentration chamber by applying a direct current resulting from a voltage normally in a range between 10 and 300 V. In this way a softened water is obtained. The current has the effect of dividing the water molecules into H + ions and OH ions. "H + ions and OH ions" keep the resin in a regenerated state. During the ion exchange procedure, the water ions, for example, tap water, are replaced by the replacement ions of the ion exchange resin. When ion exchange resins are used, which are mainly in the form of H + or OH ", the ion exchange can also be used to modify the pH of the tap water stream by proper selection and arrangement of the ion exchange resins. One or more of said confinement membranes may be in the form of what are called bipolar membranes, which consist of a layer of cation exchange membrane and pressurized anions between them in a single sheet.The desired function of this type of membrane it is a reaction of the bipolar membrane junction. Here, water is separated into H + ions and OH ions "by what is called a" disproportionation "reaction. Water separated by a bipolar membrane can be explained by looking closely at the interface between the anion and cation exchange membrane. Here, the negative groups of the cation exchange polymer are close enough to the positive groups of the anion exchange polymer to form a salt. The counterions, for example OH "and H +, move under the influence of the applied electric field, instead of recombining with the water. While in equilibrium, the salt will react with the water and return the resins to their initial state.

Definition of the invention

Surprisingly, the authors have discovered a cleaning procedure for detergent products with low environmental impact that allows one or more of the above mentioned objectives to be achieved. Accordingly, the present invention provides the cleaning process of claim 1.

For the purpose of the present invention, the feed water is defined as water having a conductivity of more than 50 micro Siemens cm "1, preferably more than 100 micro Siemens cm" 1 and more preferably more than 200 micro Siemens cm " 1. For practical reasons, the feedwater is desirably tap water from the main supply, which has a hardness of at least 7 ° FH.

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Preferably, step (iii) of the cleaning process of the invention is carried out in a washing machine or an automatic dishwasher. In view of this, the amplified water for washing has a pH greater than 8.5, preferably greater than 9.5.

The cleaning process of the invention is especially suitable for domestic use, and the AAL value obtained with said procedure is suitable for use in a domestic cleaning device.

These and other aspects, features and advantages will be apparent to those skilled in the art upon reading the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention can be used in any other aspect of the invention. It is noted that the examples provided in the following description are intended to clarify the invention, and it is not intended to limit the invention to said examples per se. In addition to the experimental examples, or where explicitly stated otherwise, all numbers that express quantities of ingredients or reaction conditions used herein should be understood as modified in all cases by the term "approximately". Similarly, all percentages are weight / weight of the low environmental impact detergent product composition, unless otherwise indicated. It is understood that the numerical intervals expressed in the format "from x to y" include x and y. When several preferred multiple intervals are described for a specific feature in the "from x to y" format, it is understood that all intervals that combine the different endpoints are also included. When the term "comprising" is used in the specification or in the claims, it is not intended to exclude any term, stage or feature not specifically indicated. All measurements are made in the international unit system, unless otherwise indicated. For example, all temperatures are in degrees Celsius (° C) unless otherwise specified. Water hardness is expressed in degrees of French hardness (° FH).

Detailed description of the invention

The amplified wash water (AAL) that is obtained as a result of step (i) of the process of the invention is especially suitable for use in a domestic cleaning device. The domestic device can be any device related to cleaning such as a washing machine, in particular a washing machine or a dishwasher. As is known, some domestic devices, particularly dishwashers, are provided with a system, also called a water softener or softener, to reduce water hardness. In particular, said system is provided to reduce the calcium and magnesium content of the water used for washing purposes, which can inhibit the action of detergents and produce calcareous deposits; In fact, calcareous deposits are due to an excessive amount of calcium ions (Ca2 +) and magnesium ions (Mg2 +) contained in the water supplied by the network. Ion exchangers to remove hardness ions (Ca2 + and Mg2 +) from water that are applied in some current dishwashers, often use Na + as the so-called replacement ions. Water flows through the resin, and the water hardness ions are exchanged for the resin replacement ions. The resin is depleted when the mayone of the substitution ions have been replaced by hardness ions. To recover the resin, which is also called regenerating the resin, a strong recovery ion solution is generally applied to the resin. In view of the above description, said regeneration procedure is undesirable.

Accordingly, the present invention has, among others, the objective of providing a method of treatment of the wash water in which the feedwater is successively contacted with a suitable combination of cation exchange resins and exchange resins anionic to produce an amplified wash water (AAL) that has more than 0.5 different pH units of feedwater and a water hardness of less than 5 ° FH, and in which the resins are regenerated by using an electric field The regeneration of the resins is preferably carried out using electrodeionization (EDI).

To be effective for washing procedures, the AAL must meet a number of requirements. First, the water hardness is less than 5 ° FH, preferably less than 2 ° FH and more preferably less than 1 ° FH. The reduction of water hardness is something necessary to avoid the deposition of soaps on the dirt, to avoid the precipitation of anionic surfactants, to maximize the stability of the colloid and to reduce the calcium-dirt-substrate interaction and the dirt-interaction dirt to improve dirt removal in this way. Finally, the pH of the AAL is an important parameter. As explained above, the pH of a conventional washing solution is usually maintained above 10 to improve the removal of fatty dirt and particles. Thus, the pH of the AAL for the average wash is greater than 8.5, preferably greater than 9.5.

The AAL has a pH value that is more than 0.5 pH units, preferably more than 1.0 pH unit, more preferably more than 1.5 pH units different from the feed water.

The properties of the AAL can be adjusted using the appropriate combinations of ion exchange resins. Ion exchange resins can be a salt, acid or base in a solid form that is insoluble in water but is hydrated. The exchange reactions occur in the water retained by the ion exchanger. An ion exchange resin consists of a polymer matrix and functional groups that interact with ions. Examples of well known polymer matrices are polystyrene resins, phenol resins.

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formaldehyde, polyalkylamine resins and poly (acrylic acid) resins. In general, four main categories of ion exchange resins can be distinguished as a function of the acidic or basic strength of the functional groups on the surface of the respective resins, that is, strongly acidic - weakly acidic - weakly basic - and strongly basic. For this particular application, cation exchange resins in the H + form and anion exchange resins in the OH form are especially preferred, although other types can also be used. Acid-or basic-strength of ion exchange resins is expressed respectively by the value of pKa for acid resins and the value of pKb for basic resins. The acid-and base-dissociation reactions attached can be written as:

(1) HA or A- + H + (acid dissociation)

(2) BOH or B + + OH- (basic dissociation)

For the present invention, the pKa value of the acidic cation exchange resin is defined as the pH of the water that comes into contact with the acidic resin, wherein the number of functional groups in the HA form is 10 times greater than the number of functional groups in the form A-. The pKb value of the basic anion exchange resin is defined as the pOH of the water that comes into contact with the basic resin, where the number of functional groups in the BOH form is 10 times greater than the number of functional groups in the form B-.

Strongly acidic cation exchange resins have a pKa value <3 and, for example, have sulfonic acid functional groups. Examples of strongly acidic cation exchange resins are, but are limited to Amberjet 1200 H, 1200 Na, 1500 H, Amberlite IR100 Na, IR120 H, IR120 Na, IR122 Na, SR1L, Amberlite 200C Na, 252 H, 252 Na, 252RF H, 252 H, Imac C16NS (all from Rohm & Haas), Lewatit Monoplus S100, S110 H, S100LF, SP112, Monoplus SP112 (all from Bayer), Dowex Monosphere C600 H, C600, Marathon CH, HGRW, HCRS (E0 , HCRS H, HCRS, HGR, MSC H, MSC Na 88, Marathon MSC (all from Dow), Diaion SK1B, SK110, PK220 (Mitsubishi), PFC100 H, PCF100, C120E, C100MB H, C100, C100x10, C100E, PF100E , C150 H, C150, C150FL, C150TL (all of Purolite), Impact CS398UPS, CS399UPS, C249, C399, CFP110 (all of Sybron).

The weakly acidic cation exchange resins have a value of 3 <pKa <9 and for example have carboxylic acid functional groups. Examples of weakly acidic cation exchange resins are, for example, but not limited to, Amberlite IRC 86, IRC50, IRC76, IRC86RF, IRC86SB, Imac HP333, Imac HP336 (all of Rohm & Haas) and Lewatit CNP80, CNP80WS, CNPLF ( all from Bayer), Dowex MAC3, CCR2, Upcore, MAC3LB (all from Dow), Diaion WK10, WK20, WK40 (all from Mitsubushi) and SR10 and CCP (Sybron).

The weakly basic anion exchange resins have a value of 5 <pKa <9 and for example they have functional groups of tertiary or quaternary amine. Examples of weakly basic anion exchange resins are, but are limited to Amberlite IRA67, IRA67RF, IrA95, IRA96, IRA96RF, IRA96SB (all from Rohm & Haas), Lewatit POC1072, MP64 (all from Bayer), Dowex MWA1, Monosphere WB500 , MWA1Lb (all from Dow), Diaion WA10, WA20, WA30 (all from Mitsubushi), A103S, A845, A847, A845FL, A100, A100FL, A100DL (all from Purolite), A328, A329 (Sybron).

Strongly basic anion exchange resins have a pKa value <6 and for example they have functional groups of quaternary amine, quaternary ammonium, quaternary phosphonium and tertiary sulfonium. Examples of strongly basic anion exchange resins are, but are limited to Amberjet 4200 Cl, 4400 OH, 4400 Cl, 4600 Cl, Amberlite IRA402 Cl, IRA402 OH, IRA404 Cl, IRA410 Cl, IRA458 Cl, IRA458 RF Cl, IRA900 Cl , IRA900RF Cl, IRA910 Cl, IRA958 Cl, Ambersep 900 SO4 Imac HP555 (all from Rohm & Haas), Lewatit Monoplus M550, Monoplus M600, M500, M511, M610, VPOC1071, VPOC1073, MP500, Monoplus MP500, MP600, VPOC10, SNOC (all from Bayer), Dowex Marathon A Monosphere A625, Marathon ALB, Marathon A2, Marathon A2 500, SBRP, SAR, MSA1, Marathon MSA, MSA2 (all from Dow), Diaion SA10A, SA11A, SA20A, PA308, PA312, PA412 , PA416 (all of Mutsubishi), PFA400, PFA300, A400, A400MB OH, A420S, A444, A200, A300, A850, A850FL, A870, A500, A500PS, A500FL, A510, A860, A500TL, A520E (all of Purolite), Impact AG1P UPS, AG1 UPS, AG2 UPS, ASB1P, ASB2, A641, A651, A642, SR7 (all of Sybron).

Another type of ion exchange resin is the so-called mixed resin, for example, but not limited to, Amberlite MB6113, MB20, MB9L, Lewatit SM92, Dowex MB50, MB500, IND, MB400, MB46 and NM65. Other types of electroactive media include, but are not limited to, zeolite resin material, sintered active carbons, hyper-crosslinked sorbent resins such as PUROLITE® HYPERSOL-MACRONET® sorbent resins (trademarks of Purolite Company, Bala Cynwyd, Pa.) , synthetic carbonaceous adsorbents, such as AMBERSORB® carbonaceous adsorbents (trademark of Rohm & Haas Corporation) and G-BAC® adsorbents (trademark of Kureha Chemical Industry Co., Ltd., Japan), polymer adsorbent resin beads which are prepared by making alkaline bridges between crosslinked copolymer beads modified with porogen and haloalkylated, having microporosities in the range of about 0.2 and 0.5 cm3 / cm, mesoporosities of at least about 0.5 cm3 / g, and a total porosity of at least about 1.5 cm3 / g as disclosed for example, Stringfield, in US Patent No. 5,460,725, and catalytic carbon as disclosed for example, by Hayden, in U.S. Patent No. 5,444,031, and Matviya et al., in U.S. Patent No. 5,356,849. One of the possible problems that may occur when the supply water is softened and its pH adjusted by electrodeionization is the risk of formation of insoluble Ca deposits. These deposits are formed under conditions of high concentration of Ca2 + and high pH. Thus, the pH of

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Ion exchange beads should be kept less than 11 to prevent precipitation of Ca (OH) 2 and preferably less than 9 to prevent precipitation of CaCO3. Especially, when a weakly acidic cation exchange resin is used for water softening, the pH of the water during the softening stages should preferably be less than 7 to maximize the selectivity to remove Ca2 + with respect to Na +, which is what It is desired for this application. However, in the case of using a weakly acidic cation exchange resin, the pH of the water during the softening process should not be less than 5 to maintain a driving force for the exchange of Ca2 + with the exchange ions of the resins, which are preferably H + ions. When, in the descriptions, Ca2 + is cited, it should also be clear that the other hardness ion, Mg2 +, is also included.

The present invention is illustrated by the following non-limiting embodiments, as shown schematically in Figures 1--21. It is emphasized that these figures provide a schematic representation, and are not intended to show the preferred amount and ratio of different types of resins. .

The relationship between the different materials of the ion exchange resins as indicated below is defined as the relationship by weight between the weight of the cationic resin material and the weight of the anionic resin material applied in the process of the invention.

In Figure 1, an embodiment of the present invention is illustrated. The feedwater is contacted with one or more (n = 1,2, 3 ... n) assemblies consisting of a first weakly acidic cation exchange resin and a second weakly basic anion exchange resin that are mainly in the forms H + and OH "respectively, and which are located inside an EDI module. The advantage of using a weakly acidic cation exchange resin to soften the water in this application, as compared to a high acidic cation exchange resin, its high selectivity for Ca2 + with respect to Na +, thus using its capacity in a more efficient way for softening. The weakly basic anion exchange resin will exchange anions for OH "and, therefore, the pH of the softened water leaving the EDI module It has a pH of approximately 9. Clearly, the pH will depend on the pKb of the selected basic resin. In cases where n = 2 or higher, water can be softened even more efficiently with a weakly acidic cation exchange resin. As the Ca2 + is removed from the water, it is exchanged for H + and, therefore, the water becomes more acidic. However, if the pH of the softening water approaches the pKa of the weakly acidic cation exchange resin, the net exchange of Ca2 + will be greatly reduced, limiting the effectiveness of the weakly acidic cation exchange resin to soften the water. In the case of a weakly acidic resin, the pKa will be about 4 and, therefore, the pH of the water preferably has to remain above about 5 to ensure an effective softening process. Once the weakly acidic cation exchange resin has been contacted, the softened water is subsequently contacted with the weakly basic anion exchange resin that increases the pH of the water. The advantage of applying a weakly basic anion exchange resin is that the pH will never exceed the pKb of the resin, which in the case of weakly basic anion exchange resins can be approximately 9. This means that the risk of forming is reduced. Ca deposits as mentioned above. In cases where n = 2 or higher, the alkaline water is subsequently contacted with the weakly acidic cation exchange resin of the second set. As the pH of said water is approximately 9, the weakly acidic resin is again capable of exchanging Ca2 + for 2H + and, therefore, more efficient water softening can be achieved. The ratio between the weakly acidic cation exchange resin and the weakly basic anion exchange resin is preferably greater than 1, more preferably greater than 1.5 and most preferably greater than 2.

Another embodiment is graphically depicted in Figure 2. In this case, the feedwater is first brought into contact with one or more (n = 1, 2, 3 ... n) assemblies consisting first of a weakly acidic cation exchange resin and, second, a resin of strongly basic anion exchange which are mainly in the form of H + and OH ", respectively. The relationship between the weakly acidic cation exchange resin and the strongly basic anion exchange resin is preferably greater than 1, more preferably greater than 2 and more preferred greater than 4 (this ratio may vary for sets n> = 2).

Another embodiment is graphically depicted in Figure 3. In this case, the feedwater is first brought into contact with one or more (n = 1, 2, 3 ... n) assemblies consisting first of a strongly acidic cation exchange resin and, second, a resin of strongly basic anion exchange which are mainly in the form of H + and OH ", respectively. The ratio between the weakly acidic cation exchange resin and the strongly basic anion exchange resin is preferably greater than 0.5, more preferably greater than 1 and most preferred greater than 2 (this ratio may vary for sets n> = 2).

Another embodiment is graphically depicted in Figure 4. In this case, the feedwater is first contacted with a weakly basic anion exchange resin and subsequently with one or more (n = 1,2, 3 ... n) assemblies consisting, first of all , a weakly acidic cation exchange resin and, secondly, a weakly basic anion exchange resin. The weakly acidic cation exchange resin and the weak anion exchange resin are mainly in the form of H + and OH ", respectively. The advantage of this embodiment is that the pH of the feedwater is already increased before the water enters contact with the weakly acidic cation exchange resin material of the first

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set. In this way, the level of softening that can be achieved during the first contact with the weakly acidic cation exchange is higher than that obtained in the event that the water enters pH 8, which is usual for tap water.

Another embodiment is illustrated in Figure 5. In this case, the feedwater is first contacted with a weakly basic anion exchange resin and subsequently with one or more (n = 1, 2, 3 ... n) sets consisting of a weakly cation exchange resin acid and a weakly basic anion exchange resin. Also in this embodiment, said exchange resins are mainly in the form of H + and OH-, respectively. After leaving the final set of ionic exchange resins weakly acidic and weakly basic, the softened water is contacted with a strongly basic anion exchange resin to increase the pH of the water to, for example, 11. The final pH clearly depends on the pKb of the strongly basic anion exchange resin selected. The advantage of working in this way is that Ca deposits are prevented and washing water can still be produced with a pH very suitable for washing. In another embodiment (see Figure 6), it is shown that it is not necessary to contact the water with a strongly basic anion exchange resin in the final stage of the process, as indicated in Figure 5. In this case, the water softened from the weakly acidic final cation exchange resin is directly contacted with the strongly basic anion exchange resin. In another preferred embodiment (shown in Figure 7), the feedwater is contacted with one or more (n = 1, 2, 3 ... n) consisting of a weakly acidic cation exchange resin and a resin of weakly basic anion exchange that are mainly in the form of H + and OH-, respectively. After leaving the final set of the ionic exchange resin weakly acidic and weakly basic, the softened water is brought into contact with a strongly basic anion exchange resin to increase the pH of the water to, for example, 11. The final pH will clearly depend of the pKb of the strongly basic resin selected.

Another preferred embodiment is graphically depicted in Figure 8, in which the feedwater is contacted with a mixed bed composed of a weakly acidic cation exchange resin and a weakly basic anion exchange resin which are mainly in the form of H + and OH-, respectively. After leaving this mixed bed, the softened water is contacted with a weakly basic anion exchange resin to raise the pH of the water to, for example, 9. By using a mixed bed of a resin of

weakly acid cation exchange and a weakly basic anion exchange resin, the pH of the water

softened can be maintained within the desired pH range of about 5 and about 9. Thus, the optimal removal of Ca2 + is combined with a reduced risk of formation of Ca deposits. The relationship between the weakly acidic cation exchange resin and the resin weakly basic anion exchange is preferably greater than 1, more preferably greater than 1.5 and most preferably greater than 2. Alternatively, after leaving this mixed bed, the softened water can be brought into contact with a strongly anionic exchange resin. basic to increase the pH of the water to a value of, for example 11 (see Figure 9).

Another embodiment is graphically depicted in Figure 10 in which the feedwater is contacted with a mixed bed consisting of a weakly acidic cation exchange resin and a strongly basic anion exchange resin that are mainly in the form of H + OH-, respectively. After leaving this mixed bed, the softened water is contacted with a weakly basic cation exchange resin to raise the pH of the water to, for example, 9. By using a mixed bed of a resin of

weakly acidic cation exchange and a strongly basic anion exchange resin in the relationship

adequate, the pH of the water to be softened can be maintained in the desired pH range of about 5 and about 9 and therefore, the optimal removal of Ca2 + is combined with a reduced risk of formation of Ca deposits. The relationship between the resin weakly acidic cation exchange and the strongly basic anion exchange resin is preferably greater than 1, more preferably greater than 2 and most preferably greater than 4.

Alternatively, after leaving this bed mixed, the softened water can be contacted with a strongly basic anion exchange resin to increase the pH of the water to a value of, for example 11 (see Figure 11). The ratio between the weakly acidic cation exchange resin and the strongly basic anion exchange resin is preferably greater than 1, more preferably greater than 2 and most preferably greater than 4.

In another embodiment (as shown in Figures 12 and 13), the feedwater is contacted with a strongly acidic cation exchange resin and then with a weakly basic anion exchange resin to increase the pH of the softened water, by example, up to 9 or with a strongly basic anion exchange resin. The ratio between the strongly acidic cation exchange resin and the weakly basic anion exchange resin is preferably greater than 1, more preferably greater than 0.5 and most preferably greater than 2.

In another embodiment (see Figure 14), the feedwater is first contacted with a mixed bed composed of a strongly acidic cation exchange resin and a weakly basic anion exchange resin which are mainly in the form of H + and OH-, respectively. After leaving this mixed bed, the softened water is brought into contact with a weakly basic anion exchange resin to raise the pH of the water to, for example, 9. Alternatively, after leaving the mixed bed, the softened water can be placed in

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contact with a strongly basic anion exchange resin to increase the pH of the wash water to, for example, 11 (see Figure 15). The ratio between the strongly acidic cation exchange resin and the weakly basic anion exchange resin in the mixed bed is preferably greater than 1, more preferably greater than 1.5 and most preferably greater than 2.

In another embodiment (as shown in Figure 16), the feedwater is first contacted with a mixed bed composed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin which are mainly in the H + and OH- form, respectively. After leaving this mixed bed, the softened water is contacted with a weakly basic anion exchange resin to raise the pH of the water to, for example, 9. The relationship between the strongly acidic cation exchange resin and the anion exchange resin Strongly basic in the mixed bed is preferably greater than 1, more preferably greater than 1.5 and most preferably greater than 2. Alternatively, (see Figure 17), after leaving the mixed bed, the softened water can be placed in contact with a strongly basic anion exchange resin to increase the pH of the wash water to, for example, 11.

In a preferred embodiment (see Figure 19), the feedwater is contacted with a mixed bed composed of a weakly acidic cation exchange resin and a strongly basic anion exchange resin which are mainly in the form of H + and OH - respectively. The resulting wash water has a reduced hardness, and the pH can vary between 5 and even 9 depending on the respective pKa and pKb values of the weakly acidic and strongly basic ion exchange resins and the relationship between them. The ratio between the weakly acidic cation exchange resin and the strongly basic anion exchange resin in the mixed bed is preferably greater than 1, more preferably greater than 2 and most preferably greater than 4.

In yet another embodiment (see Figure 20), the feedwater is contacted with a mixed bed composed of a strongly acidic cation exchange resin and a weakly basic anion exchange resin which are mainly in the form of H + and OH - respectively. The resulting wash water has a reduced hardness, and the pH can vary between 3 and even 9 depending on the respective pKa and pKb values of the strongly acidic and weakly basic ion exchange resins and the relationship between them. The ratio between the weakly acidic cation exchange resin and the weakly basic anion exchange resin in the mixed bed is preferably greater than 0.5, more preferably greater than 1 and most preferably greater than 2.

In another embodiment (see Figure 21), the feedwater is contacted with a mixed bed composed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin which are mainly in the form of H + and OH- respectively. The resulting wash water has a reduced hardness, and the pH can vary between 3 and even 9 depending on the respective pKa and pKb values of the strongly acidic and weakly basic ion exchange resins and the relationship between them. The ratio between the weakly acidic cation exchange resin and the weakly basic anion exchange resin in the mixed bed is preferably greater than 0.5, more preferably greater than 1 and most preferably greater than 2.

The contact time of the water being treated and the ion exchange resins is an important parameter. The contact time in the present invention is defined as the ratio between the total volume of the combined ion exchange resins that come into contact with the water to be treated and the flow rate of said water.

Contact time [s] = total volume of resin in contact with water [l] / water flow [l min-1]

For reasons of minimizing equipment cost and size, the total volume of ion exchange resins is kept as low as possible. However, sufficient contact time between water and ion exchange resins is required to allow the ion exchange reaction to run partially, but not entirely. Thus, the total resin volume depends on the hardness of the feed water, and will be at least 0.1 l for very low hard water and a maximum of 4 l for very high hard water. The total volume of the resin that comes into contact with the water to be treated is preferably less than 4 l, more preferably less than 3 l and most preferably less than 2 l but more than 0.1 l.

Another consideration is the filling rate of the treated water inside the device, which is preferably greater than 0.25 l min-1 for reasons of user comfort. The maximum flow is limited by the maximum filling rate from a conventional tap connection, which is approximately 15 l min-1. The preferred filling rate is greater than 0.25 l min-1, more preferably greater than 1.0 l min-1 and most preferably greater than 2 l min-1 but less than 15 l min-1. Based on these considerations, the contact time as defined above will preferably be greater than 0.01 min, more preferably greater than 0.1 min and most preferably greater than 0.3 min, but less than 2 min.

Another important parameter of the process in the present invention is the maximum allowable pressure coffee for the water treatment device. The pressure coffee will be determined, especially, by the size of the resin particles that are present, that is, the smaller the size of the particles, the greater the

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pressure coffee On the other hand, the smaller the size of the particles, the greater the area of contact between the resin and the water per unit volume. The diameter of the resin particles is defined as the ratio between the volume and the outer surface area of the resin particle. Based on these considerations, the average particle size of the ion exchange resins is preferably greater than 0.05 mm, more preferably greater than 0.1 mm and most preferably greater than 0.5 mm, but less than 10 mm. In this regard, the porosity of the ion exchange compartments also represents an important criterion. Porosity in this case is defined as:

Porosity [-] = volume of ion exchange material [L] /

volume of the compartment containing the ion exchange resins [L].

For reasons of limiting the pressure coffee while minimizing the volume of the ion exchange resin vessel, the porosity is preferably less than 0.8, most preferably less than 0.6 and preferably greater than 0.2.

Cleaning procedure

In the cleaning process of the invention, the amplified wash water obtained as a result of the water treatment stage (i) is mixed in stage (ii) with a low environmental impact detergent product (LEIP) and used for Treat the substrates to be cleaned. Said cleaning procedure is preferably carried out in a washing machine or automatic dishwasher.

Detergent booster additives

It is estimated that the majority of laundry detergent products sold in most parts of the world are conventional granular detergent products. These usually comprise more than 15% by weight of a detergent builder additive. Detergent builder additives are added to improve detergency, but detergent builder additives are recognized for their effect on eutrophication. To overcome this problem in many countries - especially those in which phosphates are banned, zeolites have become the industry accepted pattern. The LEIP used in accordance with the invention is substantially free of detergent builder. Practically free of detergent builder additive for the purposes of the present invention means that the LEIP comprises from 0 to 5% by weight of the detergent builder additive by weight of the total LEIP composition. Preferably, the LEIP comprises from 0 to 3% by weight, more preferably from 0 to 1% by weight, most preferably from 0% by weight of the detergent reinforcing additive by weight of the total LEIP composition.

The materials of the detergent builder additive are, for example 1) calcium sequestrant materials, 2) calcium precipitating materials, 3) calcium exchange materials and 4) mixtures thereof.

Examples of detergent builder additive materials that sequester calcium include alkali metal polyphosphates, such as sodium tripolyphosphate; nitriloacetic acid and these are water soluble salts; alkali metal salts of carboxymethyloxysuccmic acid, ethylenediaminetetraacetic acid, succinic oxidyl acid, melttic acid, benzenepolycarboxylic acid, citric acid; and poly (acetal carboxylates) as disclosed in US Patents 4,144,226 and 4,146,495, and the dipicolic acid and its salts. Examples of precipitating detergent builder additive materials include sodium orthophosphate and sodium carbonate.

Examples of detergent builder additive materials for calcium ion exchange include different types of water-insoluble crystalline or amorphous aluminosilicates, of which zeolites are the best known representatives, for example, zeolite A, zeolite B (also known as Zeolite P), zeolite Q, zeolite X, zeolite Y, and also the type of zeolite P described in EP-A-0384070. In addition, polymeric detergent builders, such as polyacrylates and polyimaleates. Although the soaps may have a detergent-enhancing additive function for the purposes of the present invention, the soaps are not considered to be detergent-strengthening additives, but surfactants.

Surfactants

The LEIP used in the cleaning process of the invention comprise at least 10% by weight, preferably at least 25% by weight, more preferably at least 40% by weight of a surfactant. In most cases, any surfactant known in the art can be used. The surfactant may comprise one or more anionic, cationic, non-ionic or tionic surfactants, and mixtures thereof. Additional examples are provided in "Surface Active Agents and Detergents" (Vol. I and II by Schwartz, Perry and Berch). Surfactants are also disclosed in a general manner in U.S. Patent No. 3,929,678, issued December 30, 1975 to Laughlin, et al, in Column 23, line 58 through Column 29, line 23.

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55

PH modifier

Another important ingredient in conventional granular detergent products is pH modifiers. For the purposes of the present invention, the term "pH modifier" is used to describe ingredients that alter the pH, either by increasing, decreasing or maintaining the pH at a certain level. Typical examples include, but are not limited to, salts such as acetates, borates, carbonates, (di) silicates, acids such as boric acid, phosphoric acid, sulfuric acid, organic acids such as citric acid, bases such as NaOH, KOH, bases organic as amines (mono and triethanolamine). In conventional detergent products, the detergent booster additive and the pH modifier can represent up to 70% by weight of the composition. It should be noted that, for the purposes of the present invention, surfactants - even some surfactants that may have some effect on pH - are not considered a pH modifier. The LEIP according to a preferred embodiment of the invention is substantially free of pH modifier. Substantially free of pH modifier is used to describe products comprising 0 to 5% by weight of pH modifier. Preferably, the LEIP comprises from 0 to 3% by weight, more preferably from 0 to 1% by weight, most preferably 0% by weight of pH modifier by weight of the total LEIP composition.

Enzymes

Enzymes constitute a preferred component of LEIP. The selection of enzymes is left to the formulator. However, the examples herein herein illustrate the use of enzymes in the LEIP compositions according to the present invention. "Detersive enzyme", as used herein, means any enzyme that has a cleaning effect, stain removal or any other beneficial effect on LEIP. Preferred enzymes of the present invention include, but are not limited to, among others, proteases, cellulases, lipases, amylases and peroxidases.

Enzyme stabilizing system

The LEIP system herein comprises from about 0.001% to about 10% by weight of the LEIP of an enzyme stabilizing system. An embodiment comprises from about 0.005% to about 4% by weight of the LEIP of said system, while another aspect includes the range of about 0.01% to about 3% by weight of the LEIP of an enzyme stabilizing system. The enzyme stabilizer system can be any stabilizer system that is compatible with the detersive enzyme. Stabilizing systems, for example, may comprise calcium ion, boric acid, propylene glycol, short chain carboxylic acids, boronic acids, and mixtures thereof, and are designed to solve different stabilization problems depending on the type and physical form of the detergent composition.

Bleaching system

The LEIP composition used in the process of the present invention may optionally include a bleaching system. Non-limiting examples of bleaching systems include hypohalite bleach, peroxygen bleaching systems with or without an organic catalyst and / or transition metal, or transition metal in peroxygen systems. Peroxgene systems usually comprise a "bleaching agent" (source of hydrogen peroxide) and an "activator" and / or "catalyst," however, preformed bleaching agents are included. Peroxgene system catalysts include transition metal systems. In addition, certain transition metal complexes can provide a bleaching system in the absence of a source of hydrogen peroxide.

Optional cleaning agents

The LEIP may include one or more optional cleaning agents. Cleaning agents include any suitable agent to improve the cleanliness, appearance, condition and / or care of clothing. In general, the cleaning agent may be present in the compositions of the invention in an amount of about 0 to 20% by weight, preferably 0.001% by weight to 10% by weight, more preferably 0.01% by weight to 5 % by weight of the total LEIP composition.

Some suitable cleaning agents include, but are not limited to antibacterial agents, colorants, perfumes, properfumes, finishing aids, lime soap dispersants, compositional odor control agents, odor neutralizers, transfer inhibiting polymeric agents of dyes, crystal growth inhibitors, anti-fading agents, antimicrobial agents, antioxidants, anti-redeposition agents, dirt-releasing polymers, thickeners, abrasives, corrosion inhibitors, foam stabilizing polymers, processing aids, fabric softening agents, optical brighteners, hydrotropes, suds suppressors or foams, soaps or foams reinforcers, antistatic agents, dye fixers, dye abrasion inhibitors, wrinkle reduction agents, wrinkle resistance agents, dirt repellent agents, agents sunscreens, agent s anti-bleaching agents, and mixtures thereof.

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Product format

The LEIP can be dosed in any suitable format such as a liquid, gel, paste, tablet or sachet. In some cases, granular formulations may be used, although this is not preferred. In a preferred embodiment, LEIP is a non-aqueous product. Non-aqueous, for the purposes of the present invention, is used to describe a product comprising less than 10% by weight, preferably less than 5% by weight, more preferably less than 3% by weight. The non-aqueous product may be a liquid, gel or paste or encapsulated in a sachet.

It has been suggested to equip automatic washing machines with one or more detergent product containers so that the detergent product can be dosed automatically as described in EP-A-0419036. LEIP can be dosed from a single container. Alternatively, the ingredients constituting the LEIP can be dosed from separate containers as described in EP-A-0419036. Thus, in a preferred embodiment, at least one ingredient of the LEIP is automatically dosed. An advantage of a LEIP can be the small number and / or quantity of ingredients that allows a much smaller volume of the detergent product. In practice, this means that the consumer does not need to refill the containers so often, or that the containers may be smaller.

The present invention will now be illustrated with reference to the following non-limiting examples, in which parts and percentages are by weight, unless otherwise indicated.

Examples 1, A and B

The amplified wash water (AAL) was produced as follows:

Feed water from the public network (with a hardness of 16 ° FH measured in French degrees, and a pH value of 8.2) was contacted with a suitable combination of ion exchange resins, as shown in Figure 2 where n = 2. The cation exchange resin used was Dowex MAC-3 (from Dow) and the anion exchange resin used was Amberjet 4400 OH (from Rohm & Haas). These resin materials were applied in a ratio of 2.5 and the total bed volume thereof was 600 ml. The water flow over the resins was 2 l min-1. Upon contacting the feed water with said combination of ion exchange resins, an amplified wash water with a hardness of 1 ° FH and a pH of 10.8 was produced.

In Example 1, the cleansing efficiency of LEIP using the AAL produced asf was tested as follows:

Approximately 15 l of AAL were supplied to a normal automatic washing machine (Miele, type W765). The LEIP was predisolved in 1 L of AAL so that an aqueous detergent formulation composed of AAL, NaLAS (> 95% pure, eg Degussa Huls) was obtained in a concentration of 1.0 g l-1, Savinase 12TXT (eg Novozymes) in a concentration of 0.05 g l-1 and foam depressant DC8010 (eg Dow) in a concentration of 12 mg l-1. The resulting aqueous formulation containing LEIP was added to the automatic washing machine.

The automatic washing machine load consisted of 3 kg of clean white cotton and 4 samples of each of the following dirt monitors (eg CFT bv., Vlaardingen, Netherlands).

• M002 (Fat in cotton)

• WFK 10D (Cotton tallow)

• CS-216 (diluted lipstick on cotton)

• EMPA 106 (carbon black / mineral oil on cotton)

• AS-9 (Pigment / oil / milk on cotton)

The load was washed with the formulation containing LEIP at a temperature of 40 ° C using the 'normal wash for linen' program of the Miele automatic washing machine.

In Example A, a washing experiment was carried out using 15 l of tap water (with 16 ° FH and a pH value of 8.2) instead of the AAL, with the same wash load and the same wash program. washed. In this experiment, a formulation containing LEIP using the same composition as in example 1 was used, although the AAL of said formulation was replaced by said tap water.

Finally, in Example B, a washing experiment was carried out using 16 l of tap water (which has a 16 ° FH and a pH value of 8.2), and a commercial detergent product. Additionally, the same wash load and the same wash program as in Examples I and A were used. The composition of this commercial detergent product was as follows:

 Ingredient

 % in weigh

 Surfactants

 15.0

 Zeolite detergent builder

 25.0

 Tampon

 50.0

 Enzymes

 0.5

 Defoamer

 2.0

 Polymers

 0.5

 Other minor components (including perfume)

 2.5

 Water

 4,5

The corresponding cleaning results for the different dirt monitors in the three washing experiments are shown in Figure 22. The cleaning results are expressed as 'Delta R 460 *', which is the difference 5 in the reflectance of the water monitors. dirt before and after the washing experiment, measured with a spectrophotometer (type 968, X-Rite) at 460 nm.

Figure 22 clearly shows that the washing efficiency of the formulation containing LEIP with normal tap water (Comparative Example A) is significantly worse than the washing efficiency of LEIP combined with the AAL, for all dirt monitors subjected to test. Additionally, the cleaning efficacy of the formulation containing LEIP together with the AAL appears to be comparable to that of a commercial detergent formulation with tap water (Comparative Example B).

Claims (20)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 1. A cleaning procedure comprising the stages of (i) contacting feedwater successively with one or more sets of a first cation exchange resin material and secondly with an anion exchange resin material to produce an amplified wash water (AAL) having a hardness of water below 5 ° FH and a pH value that is different by more than 0.5 pH units from the pH value of the feedwater, said pH value being greater than 8.5, in which the resins are regenerate by using an electric field, (ii) mixing said AAL with a low environmental impact detergent (LEIP) product containing from 0 to 5% by weight of the total LEIP composition and comprising at least 10% by weight, preferably at least 25% by weight , more preferably at least 40% by weight, of surfactant, to obtain a wash liquor; Y (iii) treat the substrates to be cleaned with said wash liquor. 2. A cleaning process according to claim 1, wherein the feed water is tap water having a water hardness of at least 7 ° FH. 3. A cleaning process according to claim 1 or claim 2, wherein said cationic resin materials comprise exchange resins that are in the form of H +. 4. A cleaning process according to any of claims 1-3, wherein said anionic resin material comprises exchange resins that are in the form of OH ". 5. A cleaning process according to any of claims 1-4, wherein one or more bipolar membrane (s) is applied to facilitate regeneration of ion exchange resins. 6. A cleaning process according to any of claims 1-5, wherein the resins are regenerated by the use of electrodeionization (EDI). 7. A cleaning process according to any of claims 1-6, wherein said cation exchange resin is a weakly acidic resin. 8. A cleaning process according to any of claims 1-6, wherein the cation exchange resin is a weakly acidic resin and the anion exchange resin is a strongly basic resin. 9. A cleaning process according to any of claims 1-6, wherein said cation exchange resin is a weakly acidic resin and said anion exchange resin is a weakly basic resin. 10. A cleaning process according to any of claims 1-6, wherein said cation exchange resin is a strongly acidic resin and said anionic exchange resin is a strongly basic resin. 11. A cleaning process according to any one of claims 1-6, wherein the cation exchange resin is a weakly acidic resin and the anion exchange resin is a weakly basic resin, and wherein the feedwater It is first contacted with a weakly basic anion exchange resin, before step (i) of said process. 12. A cleaning process according to any of claims 1-11, wherein the conductivity of the feedwater is greater than 50 micro Siemens cm-1, preferably greater than 100 micro Siemens cm-1 and more preferably greater than 200 micro Siemens cm-1. 13. A cleaning process according to any of claims 1-12, wherein the hardness of the AAL is less than 2 ° FH, preferably less than 1 ° FH. 14. A cleaning process according to any of claims 1-13, wherein the pH of the AAL is less than 9.5. 15. A cleaning process according to any of claims 1-14, wherein the total volume of the resin material that is contacted with the water to be treated is less than 4 l, preferably less than 3 l, and more preferably less than 2 l, but greater than 0.1 l. 16. A cleaning process according to any one of claims 1-15, wherein the feedwater flow rate is greater than 0.25 l min-1, preferably greater than 1.0 l min-1 and more preferably greater than 2 l min-1, but less than 15 l min-1. 17. A cleaning process according to any one of claims 1-16, wherein the contact time between the feed water and the resin material is greater than 0.01 min, more preferably greater than 0.1 min. and most preferably more than 0.3 min, but less than 2 min. 18. A cleaning process according to any of claims 1-17, wherein the average particle size of the ion exchange resins is greater than 0.05 mm, preferably greater than 0.1 min and more preferably greater than 0.5 mm, but less than 10 mm. 19. A cleaning process according to any of claims 1-18, wherein the porosity of the ion exchange compartments containing the resin material is less than 0.8, preferably less than 0.6 and higher to 0.2. 10 20. A cleaning procedure according to any of claims 1-19, wherein the LEIP It comprises 0 to 5% by weight of a pH modifier. 21. A cleaning process according to any of claims 1-20, wherein step (iii) of said process is carried out in a domestic cleaning device, preferably a washing machine or a dishwasher. fifteen